- Accueil »
- Entropy measurement in quantum systems

Le contenu de cette page n’est pas disponible en français. Veuillez nous en excuser.

Playing this video requires the latest flash player from Adobe.

Download link (right click and 'save-as') for playing in VLC or other compatible player.

Speaker(s):

Scientific Areas:

Collection/Series:

PIRSA Number:

17030085

Entropy is an important information measure. A complete understanding of entropy flow will have applications in quantum thermodynamics and beyond; for example it may help to identify the sources of fidelity loss in quantum communications and methods to prevent or control them. Being nonlinear in density matrix, its evaluation for quantum systems requires simultaneous evolution of more-than-one density matrix. Recently in [1] a formalism for such an evolution has been proposed and [2] shows that the flow of entropy between two systems corresponds to the full counting statistics of physical quantities that are exchanged between them. Interestingly, in quantum systems with heat dissipations this will not be equivalent to the second law of thermodynamics. In this talk I will describe a consistent formalism to evaluate entropy and show how to measure it in some quantum systems; for example in quantum point contacts in nanoelectronics and in the quantum heat engines introduced to describe photosynthesis and photovoltaic cells. The entropy flow is made of two parts: 1) an incoherent part, which can be re-evaluated semiclassically from the second law, and 2) a coherent part, which has no semiclassical analogue and appear as a result of extending Kubo-Martin-Schwinger (KMS) correlations.

[1] M.H.A. and Y. Nazarov, Phys. Rev. B 91, 104303 (2015)

[2] M.H.A. and Y. Nazarov, Phys. Rev. B 91, 174307 (2015)

Share This PageShare this on TwitterShare on FacebookPublish this post to LinkedInSubmit this post on reddit.com

©2012 Institut Périmètre de Physique Théorique